Chapter 2 Methods Flashcards
Empiricism
The belief that accurate knowledge can be acquired through observation.
Scientific Method
A set of principles about the appropriate relationship between ideas and evidence.
Theory
A hypothetical explanation of a natural phenomenon.
Hypothesis.
A falsafiable prediction made by a theory.
Rule of Parsimony for Theory
Find the simplest theory.
William Ockham
K.I.S.S.
Evidence never ___ theory.
Proves.
Empirical Method
A set of rules and techniques for observation.
Operational Definition
A description of a property in concrete, measurable terms.
Two kinds of methods that help overcome the difficulty in studying humans:
Observataion, which determines what they do, and explanation, which determines why they do it.
Good measures have three things:
Validity, reliability, and power.
Measure
A device that can detect the condition to which an operationl definition refers.
EMG
Electromyograph, a device that measures muscle contractions under the surface of a person’s skin.
Validity
The extent to which a measurement and a property are conceptually related.
Reliability
The tendency for a measure to produce the same measurement whenever it is used to measure the same thing.
Power
The ability of a measure to detect the concrete conditions specified in the operational definition.
Demand Characteristics
Thse aspects of an observation; setting that cause people to bahave as they think they should.
Naturalistic Observation
A technique for gathering scientific information by unobtrusively observing people in their natural environments.
Cover Stories
Misleading explanations that are meant to keep people from discerning the true purpose of of an observation.
Filler Items
Pointless measures that are designed to mislead you about the true purpose of the observation.
Expectations can influence ___ and ___.
Observations, reality.
Double Blind
An observation whose true purpose is hidden from both the observer and the person being observed.
Frequency Distribution
A graphical representation of measurements arranged by the number of times each measurement was made.
Normal Distribution
A mathematically defined frequency distribution in which most measurements are concentrated around the middle.
Mode
Most frequently occuring measurement.
Mean
Average of measurements.
Median
Middle memasurement.
Descriptive Statistics
Brief summary statements that capture essential information about frequency distribution.
Two types of descriptive statistics:
Central tendency and variability.
When a graph is positively skewed, the mean, median, and mode are shifted…
Left.
When a graph is negatively skewed, the mean, median, and mode are shifted…
Right.
Range
The value of the largest measurement in a frequency distribution minus the value of the smallest frequency.
Standard Deviation
A statistic that describes the average difference between the measurements in a frequency distribution and the mean of that distribution.
Scientific research aims to establish…
Causal relationships between properties.
Variable
A property whose value can vary across individuals or over time.
Correlation
Two variables are said to be correlated when variations in the value of one variable are synchronized with variation in the value of the other.
Positive Correlation
More-more or less-less.
Negative Correlation
More-less or less-more.
Correlation Coefficient
Measure of the direction and strength of a correlation.
Natural Correlation
A correlation observed in the world around us.
Third-Variable Correlation
The fact that two variables are correlated only because each is causally related to a third variable.
Matched Samples
A technique whereby the participants in two groups are identical in terms of a third variable.
Matched Pairs
A technique whereby each participant is identical to one other participant in terms of a third variable.
Third Variable Problem
The fact that a causal relationship between two variables cannot be infererred from the naturally occuring correlation between them because of the ever-present possibility of third-variable correlation.
Experiment
A technique for establishing the causal relationship between variables.
Experiments can eliminate differences by ___ and ___.
Manipulation and random assignment.
Manipulation
Creation of an artificial pattern of variation in a variable on irder to determine its causal powers.
Independent Variable
The variable that is manipulated in an experiment.
Experimental Group
The group of people who are treated in a particular way, as compated to the control group, in an experiment.
Control Group
The group of people who are not treated in the particular way that the experimental group is treated in an experiment.
Dependent Variable
The variable that is measured in a study.
Self-Selection
A problem that occus when anything about a person determines whether he or she will be included in the experimental or control group.
Random Assignment
A procedure that uses a random event to assign people to the experimental or control group.
Internal Validity
The characteristic of an experiment that establishes the causal relationship between variables.
External Validity
A property of an experiment in which the variables have been operationally defined in a normal, typical, or realistic way.
Population
The complete collection of participants who might possibly be measured.
Sample
The partial collection of people drawn from a population.
Case Method.
A method of gathering scientific knowledge by studying a single individual.
Random Sampling
A technique for chooseing participants that ensures that every member of a population has an equal chance of being included in the sample.
Informed Consent
A written agreement to participate in a study made by an adult who has been informed of all risks that participation may entail.
Debriefing
A verbal description of the true nature and purpose of the study.
